It is well-known that electronic equipment, such as a lap-top personal computer commonly is transported by the owner in a portfolio or briefcase.
It is also well-known that cases for transporting articles, such as camcorders, cameras, lap-top computers, and also portable electronic scientific instruments, commonly are padded with a shock-absorbing material, typically, padded velvet, or a foamed plastics material.
Commonly, in addition to providing a shock-absorbent padding for the article to be carried, such cases commonly are provided with straps for retaining the article against displacement within the padding.
Materials such as velvet or foamed plastics material tend to build up electrostatic charges, particularly in the event that the article being carried can rub or slide relative to the padding, and in turn, tend to attract and become contaminated with dust and other air-borne particulate materials. Further, such electrostatic charges can have disastrous effects on information stored within a computer, or data stored in other articles of electronic equipment.
There has been prior proposed in U.S. Pat. Nos. 5,217,131, 4,793,123, 4,826,329, and 4,551,370, to provide a pneumatic cushion within a box or within an item of luggage, in the form of an inflatable liner that can be pressurized with air, thus to provide a pneumatic cushion for supporting the articles contained therein, and, which will act as a pneumatic spring protecting the article in the event that the box or item of luggage is accidentally dropped.
It has, however, been found that such pneumatic cushions can only absorb relatively limited force before they rupture, and further, that such pneumatic cushions occupy, when in the inflated condition, a very considerable portion of the interior volume of the box or item of luggage. Further, such pneumatic cushions can rupture when in a low pressure environment, such as an aircraft.
Experimentation has established that dropping a weight of approximately 5.9 pounds from a height of 30 inches can produce a G force in excess of 1200G. A force of this magnitude causes displacement of the stored article within the pressurized liner, and, unless the liner is made of thick and heavy material, easily can cause rupturing of the liner, and total collapse of the pressurization thereof.
Attempts to strengthen the liner have taken resort to either increasing the volume of the liner, with a consequential decrease in the available storage area within the box or the item of luggage, or, thickening of the membrane of the liner, with a consequential increase in the weight of the liner. Both approaches have disadvantages, either in reducing the interior volume of the box or item of luggage, or, increasing the weight thereof.
The major problem is that the liner can only be inflated to a relatively low pressure. If inflated to a higher pressure, this caused ballooning of the liner, with a consequential further decrease in the available storage volume of the box or item of luggage, and even greater risk of the liner rapturing when the box or item of luggage is subjected to a substantial impact. Additionally, there is a tendency for the stored article to shift within the storage volume, with an increased possibility of impaction on a comer of the stored article, this being due to the air contained within the liner being free to move randomly to a region of lower pressure within the liner.